Catalyst regenerators are used in a number of chemical process operations, including fluid catalytic cracking and catalytic dehydrogenation of lower alkanes. Conventional regenerators typically include a vessel having a spent catalyst inlet, a catalyst outlet and a distributor for supplying oxygen containing gas to the catalyst bed in the vessel. Two stage regenerators typically comprise two vessels which complete the oxygen contacting in two distinct steps. In a two stage process, the partially spent catalyst along with a gas in which the catalyst particles are entrained enter the lower vessel and rise through a riser which is capped with a riser terminator. In an outer wall of a top portion of the riser are openings, or slots, which allow the spent catalyst and product gas to exit the riser. The riser terminator typically has a cap and a plurality of arms enclosing the slots. The cap of conventional riser terminators generally resides a predetermined distance above the slots, providing internal riser space above the slots into which some of the gas and entrained catalyst particles may enter and impinge upon refluxing catalyst and the terminator cap. Such impingement with other refluxing particles causes breaking, or attrition, of some of the catalyst particles. After leaving the riser through the slots and the arms, the catalyst and gas passes into one or more cyclone separators. It is desirable to obtain separation of the catalyst and gas prior to the gas entering the one or more cyclones which will, in turn, remove >99% of the catalyst particles from the gas.